You Have Been Called to the Post Office to Assist

You have been called to the post office to assist police with a disorderly male. On scene you find a middle-aged male patient stating that he needs to be protected because the CIA is out to get him for something he did not do. As a knowledgeable EMT, you should recognize the patient's behavior as:

A) phobia.
B) bipolar.
C) anxiety.
D) paranoia.